The field of the disclosure relates generally to subsea equipment, and more particularly to connectors for use with subsea equipment.
Mooring systems designed for long term use as deployed in offshore oil and gas, wind farms, aids to navigation and other offshore deployments, are subject to extreme weather events, prolonged exposure to sea water and are designed to withstand extreme loading. Installation of any component in an offshore location is expensive, typically requiring multiple installation vessels, meticulous planning and allowances for weather and sea conditions. Installation costs can easily become $100,000 per day. As a result, the offshore installation industry and by definition, their clients, are interested in making the installation process more efficient and less risky from a health, safety, and environmental perspective.
Quick connection systems have been used for over a decade in the installation of drilling rigs and production units in the offshore oil and gas industry. Quick connection systems are favored by the offshore installation industry as they reduce the time and therefore the cost of the installation, and because they also allow mooring lines to be pre-laid on the sea floor ahead of the arrival of the platform being deployed. In addition, quick connection systems allow the anchor system for the mooring line to be preinstalled before the mooring line is connected to the subsea connector. This is a more efficient installation process as the installer can decouple the installation of the major components of the mooring system from the critical path of the platform installation, which is often plagued with cost and time overruns.
The existing designs of quick connectors rely on ball and taper technology where a male component into which steel ball bearings are embedded is inserted into a female connector. The steel balls are free to roll against an inclined plane on the male component, and so applying tension on the male component causes the steel balls to jam against the walls of the female connector. This jamming action of the steel ball bearings causes the male component to be held firmly in the female connector. By the nature of this design, the female portion of the connector is distorted during the connection process, thus potentially affecting the component's performance and its ability to be disconnected. Despite this distortion that occurs, these existing designs are marketed as being disconnectable. The ability to disconnect mooring lines is advantageous, as mooring lines can more easily be repaired in the event of a failure of another component in the mooring system. This is becoming more important as the offshore industry extends into deeper water and as the installed infrastructure is aging. However, due to the potential for distortion during connection and use, the disconnectable nature of the existing designs is unproven during real world use.
The design of mooring systems is also becoming more complex with a large variety of connectors, and with wire, chain and polyester fiber sections, meaning that a greater number of potential failure mechanisms are now possible. The existing designs utilize different material types that can be prone to galvanic corrosion. The different material types may also degrade at different rates that could affect long term performance of the device. The existing designs are very expensive, but are an alternative to manual connection methods, such as H-links and shackles. However, it would be desirable to have a device that is quickly deployed with a low failure of connection, minimal moving parts, fewer materials, and is inherently disconnectable, while being more cost-effective than the existing designs.